The present invention relates to a storage system that performs backup and recovery of data.
A storage system for storing data of an enterprise information system has been undertaking the role of protecting such data. In response to needs of data protection and the like, in the field of storage systems, a snapshot function, journal function and so on have been proposed for acquiring the replication as the copied data without stopping the enterprise information system, and, when a disaster or operational error arises, instantaneously restoring the data from its replication, or recreating the operational status at a certain time in the past (this processing is hereinafter referred to as “recovery”) have been proposed.
The snapshot function is a function for the storage system to create a replication by copying data of a storage area at such time to another storage area upon receiving a snapshot command from a computer. As a result of periodically executing the snapshot function, it is possible to intermittently acquire the replication of data. When using the snapshot function, a user is able to perform recovery at a point when a snapshot was acquired.
The journal function is a function for the storage system to create and store a journal formed from control information on writing and write data upon receiving a write request from a computer. Japanese Patent Laid-Open Publication No. 2005-18738 discloses recovery processing to be executed at a point other than the point a snapshot was created by writing write data contained in a journal in a snapshot acquired with the snapshot function. Like this, by simultaneously using the journal function and snapshot function, it is possible to perform recovery in numerous points from few snapshots.